Biomedical subjects
Publications and source records attributed to L Abraham-Inpijn.
In The Netherlands only patients with reduced defence mechanism are considered for antibiotic prophylaxis, and only in case of a total hip replacement. The extend to which the American indications will be applied in Europe, is at this moment unknown. It becomes more and more clear that the risk from providing prophylaxis is greater than the risk of a joint infection.
The treatment of medically compromised patients is becoming a frequent event in general dental practice as a consequence of the longer presence of natural teeth, an increase in life expectation and a shift towards more ambulatory medical treatment of patients with chronic diseases. Since the dentist is responsible for a correct approach of these patients, it is important that he has knowledge of interactions between medical conditions, compensating mechanisms and medical treatment and the impact of dental treatment on this. In this context, medical history taking is useful. The medical history should be taken as correct as possible, with careful interpretation of the information. Necessary preventive measures should be known.
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BACKGROUND: Due to the aging of the population on one hand and both medical and dental innovations on the other, the number of medical complications which occur during dental treatment is expected to rise. In order to prevent such complications, dental practitioners have used a medical risk-related history which includes risk determination and preventive measures (together the MRRH system). In this study, the medical complications which occurred in their practice have been compared with those recorded by a control group. METHODS: First, a tested registration form was used. In addition, the group using the MRRH system had previously attended a 1-day introductory course de voted to the MRRH system. Furthermore, a power analysis was used to determine the group sizes. The registration period was set at 1 year, during which the dentists sent in monthly reports. Only patients over the age of 18 were included, after having given their oral consent. An independent diagnosis was given of all registered medical complications by two different internists. RESULTS: A total of 208 medical complications were reported: 45 complications were reported by the 62 dentists who used the MRRH system (reference group) and 163 by the 215 dentists of the control group. First, it should be noted that some reports did not register vital signs; this is reflected in categories such as "no diagnosis," "collapse eci," and "others." Second, the study has revealed that the reference group has registered the heart rate and the frequency of breathing of patients more frequently than the control group. Also, a relatively lower percentage of complications was recorded within the reference group due to the intravenous injection of local anesthetics. CONCLUSIONS: The number of medical complications recorded in the two groups shows little variation. There is a considerable difference, however, in the nature of these complications.
The Medical Risk Related History (MRRH) has been in use for several years in the Netherlands. Since 1994 the MRRH system has been subject to research in nine European countries. Legal and ethical demands in all participating countries have been listed, and a national epidemiological analysis of pathology interfering with dental treatment has been undertaken for every participant.
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Periodontitis is a chronic destructive inflammatory disease associated with periodontopathic bacteria. In addition, autoantigens such as collagen and heat shock proteins (hsp) have been suggested to play a role. Established periodontal lesions are characterized by dense infiltrations of immune cells such as cytokine-producing CD4+ and CD8+ T cells. CD4+ T cells specific for Prevotella intermedia can be isolated from lesional gingiva, suggesting an active role for CD4+ T cells in the response to this bacterium. We therefore investigated the characteristics of a panel of 13 P. intermedia-specific CD4+ T cells generated from the peripheral blood of a patient with chronic adult periodontitis. All 13 P. intermedia-specific CD4+ T cells recognized the antigens in the context of HLA-DR. The T cell clones were mainly classified as Th0, producing comparable amounts of interferon-gamma (IFN-gamma) and IL-4, and Th2, producing high amounts of IL-4 and almost no IFN-gamma. None of the P. intermedia-specific T cell clones recognized antigens of the periodontopathic bacteria Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis and of the autoantigens collagen and hsp. The reactivity profile of the T cell clones to size-fractionated cell envelope antigens of P. intermedia indicated that P. intermedia-specific CD4+ T cell clones recognize probably five different antigen specificities in the context of the MHC class II molecules, DR7 or DR15. These results suggest that a broad panel of cell-associated protein antigens play a role in the induction of P. intermedia-specific CD4+ T cell response.
OBJECTIVE: To determine frequency and nature of medical accidents in Dutch dental practice in relation to type and time of treatment, with and without the use of the MRRH; frequency and nature of the professional assistance. METHOD: Dentists MRRH-users (n = 51) and control dentists (n = 420) recorded medical accidents by name, using a registration form, followed by an anonymous survey. RESULTS: 91 accidents were reported by name by 471 dentists. This contrasted with 300 accidents recorded by 380 dentists in an anonymous survey. No life threatening accidents were reported. Syncope and hyperventilation were frequent. Most of the accidents occurred during local anaesthesia or during treatment, as the procedure became more stressful. Two-third of the accidents could possibly have been prevented by means of a medical history. Medical assistance was requested in 6% of the cases. CONCLUSION: Life threatening disorders were not reported, possible because in the Netherlands no intravenous sedation or general anaesthetic is used in general dental practice.
The aim of the present study was to investigate whether in healthy volunteers acute changes in plasma free amino acid composition after a protein-rich test meal are reflected in the urinary and salivary concentrations of the corresponding amino acids. The ingestion of a protein-rich meal elicited a significant increase of plasma and urine amino acid concentrations. The postprandial salivary amino acid excretion showed only minor changes. For several amino acids (alanine, arginine, asparagine, glycine, threonine and valine) significant relations were observed between the increase in concentration of these amino acids in venous plasma and urine. In whole saliva, only threonine and valine showed a significant relationship with the corresponding plasma concentration. Our data suggest that the urinary amino acid excretion of several amino acids has the potential for estimating short-term changes in plasma concentrations. Determination of salivary amino acid concentrations seems less appropriate for this purpose.
Chronic periodontitis is characterized by dense infiltrations of T lymphocytes in the connective tissue, which consists mainly of gingival fibroblasts. It is becoming increasingly clear that T lymphocytes and gingival fibroblasts are capable of influencing each other. For example, the T cell cytokine interferon-gamma (IFN-gamma) is able to induce MHC class II molecules on the surface of several cell types, including gingival fibroblasts. Histological sections of chronically inflamed gingival tissue showed a great number of CD4+ and CD8+ T cells that produced IFN-gamma, and in addition showed abundant expression of MHC class II molecules on gingival fibroblasts. Therefore, we investigated whether these gingival fibroblasts acquire the capacity to carry out MHC class II-restricted functions such as antigen presentation to local T cells. In this study, we show that IFN-gamma-treated gingival fibroblasts were able to function as antigen-presenting cells (APC) for superantigen-mediated T cell proliferation. However, these fibroblasts failed to present whole-cell antigens of periodontitis-associated bacteria. Moreover, gingival fibroblasts inhibited the presentation of the whole-cell antigens of these bacteria by professional APC. This inhibition could be overcome by the addition of IL-2. These results suggest that gingival fibroblasts play an important role in the local specific immune response in chronic inflammatory periodontal lesions by regulating the response of infiltrating T cells.
The aim of this study was to establish whether a patient-administered medical risk-related history (MRRH) for dental patients was valid. The MRRH, which was developed in the Netherlands, has now been tested in Belgium, where it was completed by total of 99 patients. Their answers were compared with the results of a verbal history, taken by a physician experienced in pre-assessment control. This verbal history was considered the 'gold standard'. The sensitivity and specificity of the medical questionnaire proved to be sufficiently high (88 per cent and 98 per cent respectively) and Cohen's Kappa displayed close agreement (0.87). These figures were only slightly lower than those obtained in Holland. The MRRH is valid for the registration of medical problems in dental patients but the answers need to be checked personally by the dental practitioner. Since the present trial was a limited one, the study will be expanded to nine countries in Europe.
Changes in mean heart rate and mean systolic and diastolic blood pressure are induced in both the patient's anticipation of scheduled treatment and the actual dental treatment itself. Significant changes have been observed before application of a local anesthetic, during restorative treatment, during extractions, and when epinephrine-impregnated retraction cords were used. These cardiovascular responses may vary according to the local anesthetic used and the choice of vasoconstrictor. The individual changes in heart rate and blood pressure are affected by pain and such individual factors as age, gender, hypertension, dental experience, and psychological responses. Although for the most part the cardiovascular changes induced by dental treatment are limited and within the normal physiological variation, this review stresses the importance of eliminating pain and minimizing patient anxiety.
This article describes the 'Feedback Post AZIG', an institute to which dentists can turn for advice on medical questions. The frequency as well as the content of these questions, posed between 1991 and 1994, are considered. Dentist clearly have a need for medical feedback and this need increases every year. Given the expected increase of the number of medically compromised patients in the dental practice, the importance of both medical training to dentists and feedback possibilities should not be underestimated.
Cloning of CD8+ T cells expressing the alpha beta T-cell receptor from inflamed human gingiva revealed that at least two different subsets were found within the tissue and that these subsets were able to interact with each other. One subset produced high levels of interferon-gamma (IFN-gamma) and no interleukin-4 (IL-4) or IL-5, exhibited phytohaemagglutinin (PHA)- or anti-CD3-mediated cytolytic activity, and were CD28+. The other subset produced high levels of IL-4 in combination with IL-5, displayed no cytotoxicity and were CD28-. From the latter subset CD8+ T-cell clones were able to suppress the proliferative response of cytotoxic CD8+ T-cell clones. This suppression could be abolished by anti-IL-4 monoclonal antibodies. However, IL-4 alone was not able to induce the suppression. Our results indicate that CD8+ T cells might participate in local immune responses by the suppression of IFN-gamma-producing cells and by favouring humoral responses via the production of IL-4 and IL-5.
40-100% of pregnant women suffer from the co-called pregnancy gingivitis. The cause of pregnancy gingivitis is possible multicausal: increased plasma female sex-hormones, alteration in dental plague and perhaps Prevotella intermedia in the subgingival plague, together with alteration of immunoresponse. Increasing levels of progesterone in the gingiva as well as estrogens due to specific receptors affect vascular permeability and exudation, provoke stasis of microcirculation, increase prostaglandine E2 formation in human gingiva. Decreased gingival keratinization and capability of cell regeneration may affect the epithelial barrier. This can perhaps explain the direct dependence between progesterone and estrogens increasing and the intensification of gingivitis clinical manifestation. The experimental gingivitis model of women during pregnancy and post-partum showed identical amounts of dental plague, but clinical manifestations were more intense during pregnancy and they had a relation with increasing P. Intermedia, no statistical significance was shown in the proportion of P. gingivalis. Increasing steroid hormones can substitute for the naphtoquinone requirement of P. intermedia. Optimal oral hygiene performed during pregnancy reduced gingival swelling, redness and bleeding tendency to levels which can be considered as physiologic for the pregnant state.
Chronic periodontitis is characterized by dense infiltrations of B and T lymphocytes within the gingival connective tissue. Distinct anaerobic gram-negative bacteria as well as autoimmunity to collagen have been reported to play a role in the etiology and the pathogenesis of this disease. Here we describe the cloning and characterization of CD4+ and CD8+ T lymphocytes isolated from inflamed gingival tissue obtained from four patients with chronic periodontitis. Clones were raised with phytohemagglutinin and interleukin-2 and tested for proliferation in response to whole-cell antigens of Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, human collagen type I, and two bacterial heat shock proteins. CD4+ T-cell clones reactive with collagen type I were obtained from all four patients. Eighty percent of these clones had phenotypes resembling the mouse type 2 T helper (Th) phenotype, i.e., they produced high levels of interleukin-4 and low levels of gamma interferon. No collagen-type-I-reactive CD8+ clones were obtained. Bacterial-antigen-reactive CD4+ and/or CD8+ T-cell clones were also obtained from each patient, and the majority of the clones showed a Th0-like cytokine pattern and produced equal amounts of interleukin-4 and gamma interferon. Although most clones were reactive with P. intermedia, it seems that the immune response is not strictly directed against this particular microorganism, as clones reactive with one of the other bacteria were also obtained from two patients. We propose that collagen-specific CD4+ Th2-like T cells contribute to the chronicity of periodontitis but that their modes of activation might be controlled by Th0-like T cells specific for periodontitis-associated bacteria.
In this article some pharmacologic aspects of corticosteroids and their main medical indications are reviewed. In addition, the use of corticosteroids in dentistry and their interference with dental treatment are discussed.
In this article the physical and psychological consequences of alcohol abuse are considered. In addition the interaction between alcohol abuse and oral health and dentistry is discussed.